"pertaining to dinner" or other meal, 1820, from Latin prandium "late breakfast, luncheon," from *pram "early" (from PIE *pre-, variant of root *per- (1) "forward," hence "in front of, before, first") + edere "to eat" (from PIE root *ed- "to eat") + -al (1). OED reports it as "affected or jocose." Compare postprandial.
Thra. What, if a toy take 'em i' the heels now, and they run all away, and cry, 'The devil take the hindmost'?
Dion. Then the same devil take the foremost too, and souse him for his breakfast! [Beaumont & Fletcher, "Philaster," Act V, Scene 2, 1611]
breakfast dish of oats, fruit, and nuts, eaten with milk or yogurt, 1926, from Swiss-German, from Old High German muos "meal, mush-like food," from Proto-Germanic *mod-sa-, from PIE root *mad- "moist, wet," with derivatives referring to various qualities of food (see mast (n.2)).
1832, "grass yielding edible grain and cultivated for food," originally an adjective (1818) "having to do with edible grain," from French céréale (16c., "of Ceres;" 18c. in grain sense), from Latin Cerealis "of grain," originally "of Ceres," from Ceres, Italic goddess of agriculture, from PIE *ker-es-, from root *ker- (2) "to grow." The application to breakfast food cereal made from grain is American English, 1899.
c. 1600 (n.) "native or inhabitant of Mexico;" by 1640s (adj.) "native of or pertaining to Mexico or its inhabitants," from Mexico + -an. In the old U.S. Southwest it served as a general pejorative or dismissive adjective, much as Dutch did in the northeast: Mexican strawberries "beans;" Mexican standoff "battle that no one wins;" Mexican breakfast "a glass of water and a cigarette," etc.
mid-13c., soper, "the last meal of the day," from Old French soper "evening meal," noun use of infinitive soper "to eat the evening meal," which is of Germanic origin (see sup (v.1)).
Formerly, the last of the three meals of the day (breakfast, dinner, and supper); now applied to the last substantial meal of the day when dinner is taken in the middle of the day, or to a late meal following an early evening dinner. Supper is usually a less formal meal than late dinner. [OED]
Applied since c. 1300 to the last meal of Christ.
"external behavior (especially polite behavior) in social intercourse," late 14c., plural of manner in a specific sense of "proper behavior, commendable habits of conduct" (c. 1300).
Under bad manners, as under graver faults, lies very commonly an overestimate of our special individuality, as distinguished from our generic humanity. [Oliver W. Holmes, "The Professor at the Breakfast Table," 1858]
Earlier it meant "moral character" (early 13c.).
MANNERS-BIT, a portion of a dish left by the guests that the host may not feel himself reproached for insufficient preparation. [Rev. Joseph Hunter, "The Hallamshire Glossary," 1829]
Flare up! flare up! is all the cry, in every square and street —
No other sound salutes your ear, whoe'er you chance to meet
Where'er you ride, or walk, or sit, or breakfast, dine, or sup,
They welcome you or quiz you with "Flare up, my boy! flare up!"
[Fraser's Magazine, April 1834]